Throat plate for a tool

ABSTRACT

An improved throat plate is disclosed herein. The throat plate includes a main body, an opening in the main body for allowing a cutting tool to extend therethrough, and a retainer assembly attached to the main body for retaining the throat plate in contact with the table. Preferably the retainer assembly is pivotally attached to the main body and/or is movable between a first position contacting the table and a second position bypassing the table. The retaining assembly may pivot about an axis substantially perpendicular to a plane of the table. The retainer assembly may also include an extension that contacts underside of the table. The extension in turn may include a camming surface contacting the underside of the table.

This is a continuation of application Ser. No. 09/151,421, filed Sept.10, 1998, now U.S. Pat. No. 5,970,835.

FIELD OF THE INVENTION

This invention relates generally to throat plates for tools, preferablypower tools.

BACKGROUND OF THE INVENTION

FIG. 1 shows a power tool 10 incorporating a prior art throat plate 11on table 13. The power tool shown in FIG. 1 is a table saw, but personsskilled in the art should recognize that the invention is applicable toany tool having a cutting tool through a table, at least momentarily.Similarly, the cutting tool 12 shown in FIG. 1 is a circular blade, butpersons skilled in the art will recognize that the invention is equallyapplicable to any other cutting tools, such as drill bits, grinderwheels, sanding wheels, linear edge blade including, but not limited to,scroll saw blades, band saw blades, jigsaw blades, hole saw blades, etc.Preferably the cutting tool 12 is driven by a motor (not shown).

Throat plate 11 is typically fixedly attached to table 13 by screws 14.However, operators may want to change the throat plate 11 to accommodatewider cutting tools 12. Accordingly, it is preferable to provide athroat plate that is easy to install and/or remove.

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved throat plate isemployed. The throat plate includes a main body, an opening in the mainbody for allowing a cutting tool to extend therethrough, and a retainerassembly attached to the main body for retaining the throat plate incontact with the table. Preferably the retainer assembly is pivotallyattached to the main body and/or is movable between a first positioncontacting the table and a second position bypassing the table. Theretaining assembly may pivot about an axis substantially perpendicularto a plane of the table. The retainer assembly may also include anextension that contacts underside of the table. The extension in turnmay include a camming surface contacting the underside of the table.

Additional features and benefits of the present invention are described,and will be apparent from, the accompanying drawings and the detaileddescription below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate preferred embodiments of theinvention according to the practical application of the principlesthereof, and in which:

FIG. 1 illustrates a typical prior art throat plate installed on a powertool;

FIG. 2 is an exploded view of a throat plate according to a firstembodiment of the present invention;

FIG. 3 is a partial cross-sectional side view of the throat plateaccording to the first embodiment;

FIGS. 4 and 5 are side and front views, respectively, of a retainerassembly according to the first embodiment;

FIGS. 6A and 6B are partial cross-sectional side views of the throatplate according to a second embodiment of the present invention; and

FIGS. 7A and 7B are partial cross-sectional side views of the throatplate according to a third embodiment of the present invention.

DETAILED DESCRIPTION

The invention is now described with reference to the accompanyingfigures, wherein like numerals designate like parts. Referring to FIGS.1-5, a throat plate 20 according to the present invention is installedwithin an opening 23 on table 13. Preferably, table 13 has a lip 24 forsupporting the throat plate 20.

Throat plate 20 basically comprises a main body 22, and a slot or hole21 in the main body 22 for allowing a cutting tool to extendtherethrough. The throat plate also includes a retainer assembly 17which is pivotally attached to main body 22 via a screw 18. Retainerassembly 17 preferably has an extension 19. Extension 19 can be pivotedbetween a first position bypassing table 13 and second positioncontacting table 13 and locking throat plate 20.

Extension 19 may have a surface 25 that contacts the underside of table13 and/or lip 24. Preferably, surface 25 is inclined so that, asretainer assembly 17 is rotated, surface 25 will act as a cam and securethe throat plate. Preferably lip 24 will have a stop (not shown) tolimit the movement of extension 19, so that the user does notaccidentally pivot extension 19 past the contacting/locking position.

Main body 22 preferably has retaining tabs 15 that engage slots 16 intable 13. Accordingly, with such construction, an operator can installthroat plate by inserting the tabs 15 into slots 16, lowering the mainbody 22, and rotating screw 18, preferably less than 360°, which in turnrotates extension 19 of retainer assembly 17, securely locking throatplate 20 in place.

A second embodiment of the present invention is shown in FIGS. 6A-6B,where like numerals refer to like parts. Retainer assembly 40 comprisesa body 41, which is pivotably attached to main body 22 via a pin 45.Persons skilled in the art will recognize that, in this embodiment, body41 rotates about an axis substantially parallel to the plane of table13, whereas in the first embodiment, retainer assembly 17 rotated aboutan axis substantially perpendicular to the plane of table 13.

Body 41 preferably has an extension 42. Body 41 and/or extension 42 canbe pivoted between a first position bypassing table 13 (FIG. 6A) andsecond position contacting table 13 (FIG. 6B). Body 41 may have a wormgear 43 that meshes with the threads 44 of screw 46, so that therotational movement of screw 46 is translated into the rotational body41 and/or extension 42. Preferably screw 46 is permanently installed onmain body 22 so that it cannot be removed therefrom.

Accordingly, with such construction, an operator can install throatplate by inserting the tabs 15 into slots 16, lowering the main body 22,and rotating screw 46, which in turn rotates extension 42 of retainerassembly 40, securely locking throat plate 20 in place.

A third embodiment of the present invention is shown in FIGS. 7A-7B,where like numerals refer to like parts. Retainer assembly 30 comprisesa screw 18, preferably permanently attached to main body 22 so that itcannot be removed therefrom, a movable part 32 threadingly attached tothe screw 18 and at least one holder strip 33 attached to movable part32 and screw 18. Retainer assembly 30 may also comprise a fixed part 31fixedly attached to screw 18 and connected to the holder strip 33.

Accordingly, upon rotation of screw 18, the movable part 32 will movealong the screw 18, forcing the holder strip 33 to bend or straightenout. In other words, the holder strip 33 can be moved between a firstposition bypassing table 13 (FIG. 7A) and second position contactingtable 13 (FIG. 7B). Because the holder strip 33 will be folded andunfolded many times, it is preferable to use a long-lasting materialthat will not break upon folding, such as plastic, lead or steel.Alternatively, strip 33 can be made of two parts connected by a hinge.

With such construction, an operator can install throat plate byinserting the tabs 15 into slots 16, lowering the main body 22, androtating screw 18, which in turn moves movable part 32 and folds holderstrip 33, securely locking throat plate 20 in place.

Persons skilled in the art may recognize other alternatives to the meansdisclosed herein. However, all these additions and/or alterations areconsidered to be equivalents of the present invention.

What is claimed is:
 1. A throat plate for a tool comprising a table, thethroat plate comprising:a main body; an opening in said main body forallowing a cuffing tool to extend therethrough; and a retainer assemblyattached to the main body for retaining the throat plate in contact withthe table, wherein the retainer assembly is pivotally attached to themain body, pivots about an axis substantially parallel to a plane of thetable, and comprises an extension that contacts the table.
 2. The throatplate of claim 1, wherein the retainer assembly is movable between afirst position contacting the table and a second position bypassing thetable.
 3. The throat plate of claim 1, wherein the main body furthercomprises at least one retaining tab.
 4. The throat plate of claim 1,wherein the retaining assembly is rotatably connected to a screw.
 5. Thethroat plate of claim 4, wherein the retaining assembly is pivoted bypivoting the screw.
 6. The throat plate of claim 4, wherein theretaining assembly comprises a gear that meshes with the screw.
 7. Thethroat plate of claim 1, wherein the extension contacts underside of thetable.
 8. A tool comprising:a table; a cutting tool extending throughthe table; and a throat plate comprising:a main body; an opening in saidmain body for allowing a cutting tool to extend therethrough; and aretainer assembly attached to the main body for retaining the throatplate in contact with the table, wherein the retainer assembly ispivotally attached to the main body, pivots about an axis substantiallyparallel to a plane of the table, and comprises an extension thatcontacts the table.
 9. The tool of claim 8, wherein the retainerassembly is movable between a first position contacting the table and asecond position bypassing the table.
 10. The tool of claim 8, whereinthe main body further comprises at least one retaining tab.
 11. The toolof claim 8 wherein the cutting tool is one from the group consisting ofcircular blades, drill bits, grinder wheels, sanding wheels, linear edgeblades, scroll saw blades, band saw blades, jigsaw blades and hole sawblades.
 12. The tool of claim 8, wherein the cutting tool is driven by amotor.
 13. The tool of claim 8, wherein the retaining assembly isrotatably connected to a screw.
 14. The tool of claim 13, wherein theretaining assembly is pivoted by pivoting the screw.
 15. The tool ofclaim 13, wherein the retaining assembly comprises a gear that mesheswith the screw.
 16. The tools of claim 13, wherein the extensioncontacts underside of the table.